From c302bf6d67615b71034903f2a37b2017b69aadd0 Mon Sep 17 00:00:00 2001 From: carbotaniuman <41451839+carbotaniuman@users.noreply.github.com> Date: Fri, 12 Jun 2020 09:50:49 -0500 Subject: [PATCH] Improve DiskLruCache --- src/main/java/mdnet/cache/DiskLruCache.java | 105 +++++++------------- 1 file changed, 37 insertions(+), 68 deletions(-) diff --git a/src/main/java/mdnet/cache/DiskLruCache.java b/src/main/java/mdnet/cache/DiskLruCache.java index 5108c9b..5e2715b 100644 --- a/src/main/java/mdnet/cache/DiskLruCache.java +++ b/src/main/java/mdnet/cache/DiskLruCache.java @@ -82,9 +82,10 @@ import java.util.regex.Pattern; *
  • When an entry is being edited, it is not necessary to * supply data for every value; values default to their previous value. * - * Every {@link #editImpl} call must be matched by a call to {@link Editor#commit} - * or {@link Editor#abort}. Committing is atomic: a read observes the full set - * of values as they were before or after the commit, but never a mix of values. + * Every {@link #editImpl} call must be matched by a call to + * {@link Editor#commit} or {@link Editor#abort}. Committing is atomic: a read + * observes the full set of values as they were before or after the commit, but + * never a mix of values. * *

    * Clients call {@link #get} to read a snapshot of an entry. The read will @@ -110,7 +111,6 @@ public final class DiskLruCache implements Closeable { private static final long ANY_SEQUENCE_NUMBER = -1; public static final Pattern LEGAL_KEY_PATTERN = Pattern.compile("[a-z0-9_-]{1,120}"); - public static final Pattern UNSAFE_LEGAL_KEY_PATTERN = Pattern.compile("[a-z0-9_-][\\/a-z0-9_-]{0,119}"); private static final String CLEAN = "CLEAN"; private static final String DIRTY = "DIRTY"; @@ -412,16 +412,6 @@ public final class DiskLruCache implements Closeable { return getImpl(key); } - /** - * Returns a snapshot of the entry named {@code key}, or null if it doesn't - * exist is not currently readable. If a value is returned, it is moved to the - * head of the LRU queue. Unsafe as it allows arbitrary directories to be accessed! - */ - public Snapshot getUnsafe(String key) throws IOException { - validateUnsafeKey(key); - return getImpl(key); - } - public synchronized Snapshot getImpl(String key) throws IOException { checkNotClosed(); Entry entry = lruEntries.get(key); @@ -474,15 +464,6 @@ public final class DiskLruCache implements Closeable { return editImpl(key, ANY_SEQUENCE_NUMBER); } - /** - * Returns an editor for the entry named {@code key}, or null if another edit is - * in progress. Unsafe as it allows arbitrary directories to be accessed! - */ - public Editor editUnsafe(String key) throws IOException { - validateUnsafeKey(key); - return editImpl(key, ANY_SEQUENCE_NUMBER); - } - private synchronized Editor editImpl(String key, long expectedSequenceNumber) throws IOException { checkNotClosed(); Entry entry = lruEntries.get(key); @@ -614,17 +595,6 @@ public final class DiskLruCache implements Closeable { return removeImpl(key); } - /** - * Drops the entry for {@code key} if it exists and can be removed. Entries - * actively being edited cannot be removed. Unsafe as it allows arbitrary directories to be accessed! - * - * @return true if an entry was removed. - */ - public boolean removeUnsafe(String key) throws IOException { - validateUnsafeKey(key); - return removeImpl(key); - } - private synchronized boolean removeImpl(String key) throws IOException { checkNotClosed(); Entry entry = lruEntries.get(key); @@ -709,13 +679,6 @@ public final class DiskLruCache implements Closeable { } } - private void validateUnsafeKey(String key) { - Matcher matcher = UNSAFE_LEGAL_KEY_PATTERN.matcher(key); - if (!matcher.matches()) { - throw new IllegalArgumentException("keys must match regex " + UNSAFE_LEGAL_KEY_PATTERN + ": \"" + key + "\""); - } - } - /** A snapshot of the values for an entry. */ public final class Snapshot implements Closeable { private final String key; @@ -790,7 +753,7 @@ public final class DiskLruCache implements Closeable { * Returns an unbuffered input stream to read the last committed value, or null * if no value has been committed. */ - public InputStream newInputStream(int index) { + public synchronized InputStream newInputStream(int index) { synchronized (DiskLruCache.this) { if (entry.currentEditor != this) { throw new IllegalStateException(); @@ -806,32 +769,13 @@ public final class DiskLruCache implements Closeable { } } - /** - * Returns the last committed value as a string, or null if no value has been - * committed. - */ - public String getString(int index) throws IOException { - try (InputStream in = newInputStream(index)) { - return in != null ? IOUtils.toString(in, StandardCharsets.UTF_8) : null; - } - } - - /** - * Write a string to the specified index. - */ - public void setString(int index, String value) throws IOException { - try (OutputStream out = newOutputStream(index)) { - IOUtils.write(value, out, StandardCharsets.UTF_8); - } - } - /** * Returns a new unbuffered output stream to write the value at {@code index}. * If the underlying output stream encounters errors when writing to the * filesystem, this edit will be aborted when {@link #commit} is called. The * returned output stream does not throw IOExceptions. */ - public OutputStream newOutputStream(int index) { + public synchronized OutputStream newOutputStream(int index) { if (index < 0 || index >= valueCount) { throw new IllegalArgumentException("Expected index " + index + " to " + "be greater than 0 and less than the maximum value count " + "of " + valueCount); @@ -862,6 +806,25 @@ public final class DiskLruCache implements Closeable { } } + /** + * Returns the last committed value as a string, or null if no value has been + * committed. + */ + public String getString(int index) throws IOException { + try (InputStream in = newInputStream(index)) { + return in != null ? IOUtils.toString(in, StandardCharsets.UTF_8) : null; + } + } + + /** + * Write a string to the specified index. + */ + public void setString(int index, String value) throws IOException { + try (OutputStream out = newOutputStream(index)) { + IOUtils.write(value, out, StandardCharsets.UTF_8); + } + } + /** * Commits this edit so it is visible to readers. This releases the edit lock so * another edit may be started on the same key. @@ -966,8 +929,10 @@ public final class DiskLruCache implements Closeable { this.key = key; this.lengths = new long[valueCount]; - // Splits the keys into a list of two characters, and join it together to use it for sub-directorying - this.subKeyPath = File.separator + String.join(File.separator, key.substring(0, 8).replaceAll("..(?!$)", "$0 ").split(" ")); + // Splits the keys into a list of two characters, and join it together to use it + // for sub-directorying + this.subKeyPath = File.separator + + String.join(File.separator, key.substring(0, 8).replaceAll("..(?!$)", "$0 ").split(" ")); } public String getLengths() { @@ -1007,8 +972,10 @@ public final class DiskLruCache implements Closeable { } catch (FileAlreadyExistsException faee) { try { Files.delete(oldCache); - } catch (IOException ex) {} - } catch (IOException ex) {} + } catch (IOException ex) { + } + } catch (IOException ex) { + } } return new File(directory + subKeyPath, key + "." + i); @@ -1024,8 +991,10 @@ public final class DiskLruCache implements Closeable { } catch (FileAlreadyExistsException faee) { try { Files.delete(oldCache); - } catch (IOException ex) {} - } catch (IOException ex) {} + } catch (IOException ex) { + } + } catch (IOException ex) { + } } return new File(directory + subKeyPath, key + "." + i + ".tmp");